This experiment is designed to show the effects of different liquids on teeth. We used eggs because similar to teeth, eggshells contain calcium compounds. We prepared 4 glasses with 4 different liquids: cherry juice drink, vinegar, coffee and blackcurrant juice drink. We dropped four eggs into each glass and left them there for 24 hours to conduct the experiment. All drinks did not visibly damage eggs but coloured them into different colours. Later we tried to clean them using toothpaste, but yo

A quick tutorial of how to perform a decay test. Close off the core removal tool to isolate the system and watch for a rise in pressure. On a small system like this (9k btu) a few minutes should be good. On larger systems you'll want a longer decay. If the pressure spikes and doesn't flatten, it's most likely a leak, if its rises and flattens at 2000 microns for instance, you have some more evacuation to do. This set up had the system down below 500 microns in less than 5 minutes. Tools used in